10% of Damage is taken from Mana before Life 
As with other "Mana taken before Life" effects, this skill will deduct 10% of the damage that would be inflicted on the character's life is deducted from mana instead. If the character has insufficient mana, then the remainder of the damage will be taken from life. Damage dealt to energy shields will not be deducted from mana.
See Mind Over Matter for details on the mechanic.